Line a baking sheet with parchment paper or spray it lightly with baking spray.
In a bowl, combine the flour, baking soda, and salt; stir to blend.
In a mixing bowl with an electric mixer, beat the butter and sugars together until light and fluffy. Add the eggs, egg yolk, and vanilla; beat until well blended.
With the mixer on low, add the flour mixture until blended.
Fold in chocolate chips.
Drop the dough onto the prepared baking sheet with a cookie scoop or tablespoon, depending on how large you would like the cookies. Leave about 1 1/2 to 2 inches between cookies.
Bake for 9 to 12 minutes, or until lightly browned and set in the middle.